Self-lubricating bolt.



D. H. TWAITS.

SELF LUBRICATING BOLT.

APPLICATION FILED DEC.22.1913.'

1 9 1 55 1 1 1 Paten. 3d Sept. 28, 1915.

IE 'QT' JUL/EN/UH DANIEL H. TWAITS, OF CHICAGO, ILLINOIS.

SELF-LUBRICATING BOLT.

Specification of Letters Patent.

Patented Sept. as, 1915.

Application filed December 22, 1913. Serial No. 808,164.

T 0 all whom it may concern:

Be it known that I, DANIEL H. TwArrs, a

citizen of the United States, residing at Chicago, in the county of Cookand State of Illinois. have invented a certain new and usefulImprovement in Self-Lubricating Bolts, of which the following is a full,clear, and exact description, reference being had to the accompanyingdrawings.

This invention relates to lubricating spring bolts of a type whereinthere is a reservoir for the lubricant within the bolt, and the generalobject is to provide a simple, elfective spring bolt which may becheaply manufactured and which will be strong and durable in service. i

More specific objects are to provide sunple means to rigidly secure anangular cap on one end of a tubular member, thereby forming the head ofthe bolt and at the same time tightly close this end of the tubularmember and provide a movable cap for tightly closing the other end ofthe member and at the same time act as a nut to draw the bolt tightlyinto place.

To the above ends the invention consists in a combination of partshereinafter described and summarized in the claims.

In the drawings, Figure 1 is a plan of the bolt showing it in positionin the eye and shackles of a suitable spring; Fig. 2 1s a crosssectionof the bolt also showing the eye and shackles of the spring; Fig.3 is an end elevation of the head of the bolt; Fig. 4

" is a sectional detail of the same; Fig. 5 is a perspective view of thehead before being put in place on the tubular portlon or shank of thebolt; Fig. 6 is a detail of a sultable lock washer before being applied.

Referring to the parts by numerals: 10 1s a tubular member forming theshank of the bolt having an interior bore 11 which'when closed at theends, forms the reservoir for the lubricant. At the head end of thistubular member are formed projections or lugs 12 preferably madeintegral with the member 10 and formed by cutting away the portionsbetween these lugs, and'leaving the end of the member squared ofi'evenly between them. In making these lugs I find it convenient inremoving the metal between them, to out toward the center, whichprovides the sides of them being substantially radial, as shown.However, my invention is not limited to the exact shape or number ofthese lugs, as there may be any convenient number of them of anyconvenient shape.

The cap 14 forming the head of the bolt has an angular exterior,preferably hexagonal, and is bored out on the inside to fit tightly overthe end of the tube. A wall 15 closing the end of the cap, is providedwith openings 16 correspondingly positioned and adapted to fit over thelugs 12. At the outer side of the wall 15 these openings are chamferedto allow the ends of the lugs 12 to be upset, causing the metal toengage the cap, without leaving projections or raised por tions abovethe end surface of the cap.

After the cap 14 is forced in place on the end of the tube, and the endsof the lugs 12 have been upset to secure it in place, a hole 18 is madethrough one side of the cap and through the end of the tube 10 and isthreaded on the interior to receive a suitable screw 19 which forms atight plug for this hole. By removing the screw 19, the reservoir on theinterior of the bolt may be filled with suitable lubricant. When thisscrew is replaced, the lubricant is prevented from leaking out of thehole, at the same time dust and grit is prevented getting into thelubricant.

The opposite end of'the tube is provided with external threads 20 onwhich a threaded cap 22 is screwed when the bolt .is in place. the cap,the bore'is undercut at 23, providing a seat for a resilient washer 25which fits snugly against the end of the tube to prevent leakage of thelubricant. The exterior of this cap is angular, also preferably hex- Atthe inner end of the threads of agonal, to allow engagement by asuitable wrench for screwing it onto the tubular member. When this capis drawn into place, its inner edge, which is squared ofi to form a?shoulder, engages'the shackle and draws the bolt into place bringing thecap forming the head of the bolt, against its shackle.

Any suitable lock washer may be pro vided to securely hold the cap 22 inplace.

Such a washer is indicated'at 26, and is shown, before being used, inFig. 6... This washer is provided with humps 28 which engage suitabledepressions in the shackle 30. After the cap is in place, ears 31 on thelockwasher are raised to engage flat sides of the cap-and therebyprevent it turning.

To feed the lubricant from the interior of end to end thereof, I providea flattened portion 40 on the top side of the bolt, connecting openings32 and forming in effect a groove along which the lubricant may flow. Itis desirable that the bolt should remain in its upright position toinsure the lubricant being fed by capillary action only, which.

itself supplies suflicientlubricant, while if the bolt should becometurned over, it would feed by gravity, which might be too much and allowthe lubricant to be wasted.- Ac- 'ing lubricant to the outer surface ofthe ftubular member forming the shank of the cordingly, I provide meansfor holding the bolt in the'position with the openings 32 and the plug19 on the top side. As shown, this means is a lug 41 projecting from the.innerend of the cap 14 and engaging a suitable depression in theshackle 42.

It will be seen from the foregoing description that I have provided aspring bolt which may be very cheaply manufactured in that the shank ofthe bolt is formed of a straight piece of hollow tubing, providedwithprojections at one end and screw threads on the other- The head of. thebolt I is formed of a cap having an angular exterior andfrigidly securedto .oneend by the projections, while the nut :01? the bolt is formed bya cap having an angular exterior and threaded onto the opposite end.This bolt is thoroughly tight, there being no chancefor the lubricant toseep through the joints, and. it is strong and durable in service. I

Having thusdescribe'd myinvention, what lclaimisz 'j' 1. In a springbolt, the combination of a tubular'member forming a shank of thebolt, acap fitting over one end of the tubular member, projections .Carried bythe tubular member and engaging the cap for rigidly securing the capthereto, and means for feedshank of the bolt.

2. In a spring bolt, the combination {of a bolt, a cap tightly fittingover one 'end'of the boltand having a closed end, an opening in theclosed end thereof, a projection carried by the tubular member andengaging said openings for securely holding the cap in place, and inletand outlet passages for saidbolt.

tubular member forming the shank of'the' bolt, a cap tightly fitted overone end of the bolt and having an end wall closing the end of tubularmember and having openings through said end wall, said opening beingtubular memberhaving integral projections at the end thereof engagingsaid openings and being upset at their outer ends into the chainferedportion of the openings whereby the cap is securely held onto the end ofthe .tubular member, said bolt having inlet and outlet passages forlubricant.

5. In a spring bolt, the combination of a tubular member formingtheshank of the bolt, a cap fitted over one end of the tubular member,projections carried by the tubular chamfered at the outer side of thecap, said member and engaging the cap to securely.

hold the same in place, a lug carried by the cap for engaging theshackle of the spring to prevent the bolt turning when in place, andoutlet means leading to the outer surface of the shank.

e 6. In a spring bolt, the combinationof a tubular member forming theshank of the bolt, acap tightly, fitted over one end of said tubularmember, a projection on said tubular member engaging the cap to hold thesame in place, a passage through the cap and through the end of thetubular member whereby lubricant may be supplied to the interior of thetubular member, a closure for said passage, and outlet means leading tothe outer surface of the shank.

7 In a spring bolt, the combination of a tubular member, a' cap tightlyfitted over the end of said tubular member and having 7 openings in itsclosed end, projections carried by the tubular member engaging saidopenings, an opening through one side of the capzand-the end of thetubular member, a plugthreaded into said opening, and out- Iitrlhkeansleading to the outer surface of the S a} T8.- In'a spring bolt, thecombination of a tubular member forming the shank of the bolt, a captightly fitted over one end of the tubular member, and having an angulare11:- "terior, projections carried by the tubular member and engagingthe cap, means-for feeding. therlubricant from the 'interior of fthe'tubular memberto the exteriorthereof, and an opening through thefirst mention-edcap for supplying lubricantto the interior. v v of thetubular member. i InaSprin'gbolt, the combination. of a tubular memberforming the shank of'the .9. In a spring 'bolt, thecombination of atubular member, a cap tightly fitted over one end and having openingsthrough the end thereof, projections on the tubular member engaging theopening and being upset to hold the cap in place, a passage leadingthrough one side of said cap and through the end of said tubular member,an opening in one side of said tubular member, means for preventing thebolt turning When in position whereby said openings may remain in thedesired position, and a cap threaded onto the opposite end of the tubular member, and outlet means leading to the outer surface of the shank.

10. In a spring bolt, the combination of a tubular member, a cap fittedover one end of said tubular member and being secured thereto byprojections carried by'the tubular member, means for feeding lubricantfrom the interior of the tubular member to the exterior thereof, a capthreaded on the opposite end of the tubular member and having anenlarged cavity at the inner end of the threads, and a resilient membercarried in said cavity and engaging the end of the tubular member whenthe cap is in posit-ion.

ll. In a spring bolt, the combination of a tubular member, a cap tightlyfitted over and closing one end of the bolt and rigidly secured theretosaid cap having an angular exterior and forming the head of the bolt, acap threaded onto and closing the opposite end of the tubular membersaid last mentioned cap having an angular exterior and forming the nutof the bolt, andinlet and outlet passages for said bolt.

12. In a spring bolt, the combination of a tubular member, a cap tightlyfitted over the end of said tubular member and having openings in itsclosed end, projections carried by the tubular member and engaging saidopenings, means for preventing the turning of the bolt when in position,openings through one side of the cap and the end of the tubular memberleading to the interior of the bolt, means for closing said opening, andmeans for leading the lubricant to the outer surface of the bolt.

13. In a spring bolt, the combination of a shank having a cylindricalbore leading from end to end thereof, a cap fitting over and closing oneend of the shank, projections carried by one end of the shank andengaging the cap for rigidly securing it thereto, thereby forming thehead of the bolt, a cap threaded onto and closing the opposite end ofthe hollow shank forming the nut of the bolt, and inlet and outlet meansfor the lubricant.

In testimony whereof, I hereunto aiiix my signature in the presence oftwo Witnesses. DANIEL H. TVVAITS. lVitnesses: V

ISABEL M. PaENTrss, HENRIETTA A. ODAY.

